and have no .cmd file at all. That's how I'd do it if I was using command prompts. In AutoIt3 or some other language that does easy Guis with drop targets just drag & drop and call a file write function to zero the files in the drop list. Depends if you're primarily interested in batch... but the drop target gui, if the window is created dynamically, can just pass on creating the window if you have command line params for the files, and be dual purpose.

Ordstrin the "*.txt" was just an example. The command line "type nul > filename" will zero any file named "filename". It just overwrites the file from 'nul' which has no content, then closes the file.

You just need to decide how to substitute for "filename" with a replaceable parameter. If your main interest is using it in batch then I would read up on subcommands and keywords used in NT style .cmd files(that use cmd.exe.) There are plenty of sources on the web.